Summary

Remove the apt tool, associated API, and documentation from the JDK.

Goals

By removing apt from the JDK, annotation processing can finish
transitioning to the superior, standardized JSR 269 API.

The apt annotation processing framework is JDK-specific and dates
back to JDK 5. The functionality of the API was standardized with
JSR 269, which shipped as part of Java SE 6. In JDK 7, the entirety
of the apt API was deprecated.

Non-Goals

Developing automated tooling to convert apt annotation processors
to JSR 269 annotation processors is out of scope for this effort.

Motivation

Unlike the JSR 269 API, the apt API cannot be updated to model
language features introduced after JDK 5. Removing apt from the JDK
will also ease maintenance of javac and related tools.

Description

Implementing the removal will include removing the affected files from
the JDK 8 langtools Mercurial repository as well as supporting
makefile changes.

Testing

Any testing will be limited to verifying the apt command and API are
not present.

Risks and Assumptions

Subject to the dependency noted below, there are no engineering issues
with excising apt from the JDK. Users of annotation processing will
have ample warning apt has been removed so needed migrations can
occur before JDK 8 ships.

Dependences

Portions of jaxws are built on top of apt. These components need to
be migrated to use the JSR 269 implementation in the JDK before apt
can be removed.

Impact

After this change, users of annotation processing will have to use the
JSR 269 annotation processing facility, which has been supported in javac
since JDK 6. Since apt is just part of the JDK and not part of Java
SE, there is a looser compatibility contract around this component
than around an API in java.* or javax.*. The removal of a command
line tool from the JDK is not unprecedented, but the removal of apt
should be clearly described in the release notes and similar
documents.